Centrifugal separators are generally used for separation of liquids and/or for separation of solids from a liquid. During operation, heavy particles or denser liquid, usually water, accumulates at the periphery of a rotating container whereas less dense liquid accumulates closer to the central axis of rotation. This allows for collection of the separated fraction, e.g. by means of different collection means arranged at the periphery and close to the rotational axis, respectively.
The liquid mixture that is to be separated is usually supplied by an inlet pipe, which may be arranged close to the central rotational axis, and is then guided e.g. via inlet channels to the separation chamber, i.e. to the part of the centrifugal separator in which the actual separation occurs. However, turbulence may occur when liquid is transferred from the inlet pipe to the separation chamber, which in turn may affect the separating performance in a negative way. For example, turbulence may cause disruption of droplets, particles or agglomerates of particles in the liquid mixture, which may make separation of e.g. oil and water more difficult.
U.S. Pat. No. 5,921,909 discloses a specific inlet device for a centrifugal separator. The inlet device is easily modified such that the flow capacity may be adjusted without the number of expensive details being increased. The inlet device comprises a zone which is essentially obstacle-free for the liquid to be separated during operation.
However, there is still la need in the art for means of decreasing the risk of turbulence in the liquid that is to be separated.